pISSN 2234-3806eISSN 2234-3814
EliA, QUANTA Flash, IIFA, and anti-ENA antibody assay results in samples with discrepant automated immunoassay and IIFA results
| Case number | Diagnosis | EliA |
QUANTA Flash |
IIFA |
Anti-ENA antibodies |
|---|---|---|---|---|---|
| 1 | SLE | (P) 7.5 | (P) > 200.0 | (N) 1 : 40 | SS-A (Ro60) |
| 2 | SLE | (P) 7.3 | (P) 125.5 | (N) 1 : 40 | SS-A (Ro60) |
| 3 | CTD | (N) 0.4 | (P) > 200.0 | (N) Weak | SS-A (Ro60) |
| 4 | SjS | (P) 1.5 | (P) 29.5 | (N) 1 : 40 | SS-A (Ro60) |
| 5 | SLE | (N) 0.4 | (N) 8.1 | (P) 1 : 640 | Nucleosome |
| 6 | SLE | (N) 0.5 | (N) 9.8 | (P) 1 : 320 | Nucleosome |
| 7 | SLE | (P) 8.0 | (P) 49.1 | (N) Weak | Histone, SS-A (Ro60) |
| 8 | SLE | (P) 5.7 | (P) 111.4 | (N) 1 : 40 | Ribosomal-P, SS-A (Ro60) |
| 9 | SLE | (P) 4.7 | (N) 17.7 | (P) 1 : 160 | dsDNA, nRNP, ribosomal-P, Sm |
| 10 | SLE | (N) 0.9 | (N) 8.7 | (P) 1 : 320 | Histone |
| 11 | SLE | (N) 0.7 | (N) 11.0 | (P) 1 : 80 | Scl-70 |
| 12 | SLE | (N) 0.6 | (N) 11.7 | (P) 1 : 1,280 | ND |
| 13 | SLE | (N) 0.4 | (N) 10.8 | (P) 1 : 320 | ND |
| 14 | SLE | (N) 0.3 | (N) 15.4 | (P) 1 : 80 | ND |
| 15 | SLE | (N) 0.1 | (N) 10.3 | (P) 1 : 80 | ND |
| 16 | SLE, SjS | (N) 0.1 | (N) 8.8 | (P) 1 : 80 | ND |
| 17 | CTD | (N) 0.4 | (N) 2.6 | (P) 1 : 320 | ND |
| 18 | CTD | (N) 0.2 | (N) 5.7 | (P) 1 : 80 | ND |
| 19 | Unclassified CTD | (N) 0.2 | (N) 8.4 | (P) 1 : 160 | ND |
| 20 | Collagen disease | (N) 0.1 | (N) 3.9 | (P) 1 : 320 | ND |
| 21 | RA | (N) 0.1 | (N) 8.1 | (P) > 1 : 1,280 | ND |
| 22 | RA | (N) 0.1 | (N) 7.4 | (P) 1 : 160 | ND |
| 23 | SjS | (N) 0.4 | (N) 4.1 | (P) 1 : 80 | ND |
| 24 | SSc | (N) 0.3 | (N) 5.5 | (P) 1 : 320 | ND |
| 25 | Arthralgia | (N) 0.3 | (N) 6.6 | (P) 1 : 80 | ND |
| 26 | Arthrosis | (N) 0.2 | (N) 3.8 | (P) 1 : 80 | ND |
| 27 | Cough | (N) 0.1 | (N) 4.5 | (P) 1 : 160 | ND |
| 28 | Dry mouth | (N) 0.2 | (N) 7.5 | (P) 1 : 160 | ND |
| 29 | Hemoptysis | (N) 0.2 | (N) 6.9 | (P) 1 : 80 | ND |
| 30 | ILD | (N) 0.2 | (N) 3.8 | (P) 1 : 80 | ND |
| 31 | Oral ulcer | (N) 0.2 | (N) 3.0 | (P) 1 : 160 | ND |
| 32 | R/O FFA | (N) 0.2 | (N) 4.2 | (P) 1 : 160 | ND |
| 33 | SLE | (N) 0.2 | (P) 24.1 | (N) Weak | ND |
| 34 | SLE | (N) 0.9 | (P) 24.1 | (N) 1 : 40 | ND |
| 35 | Arthrosis | (N) 0.1 | (P) 44.7 | (N) 1 : 40 | ND |
| 36 | Rash | (N) 0.2 | (P) 131.7 | (N) Negative | ND |
| 37 | CTD | (P) 1.1 | (N) 13.6 | (N) Weak | ND |
| 38 | OA | (P) 1.7 | (N) 7.8 | (N) 1 : 40 | ND |
| 39 | SLE | (P) 1.7 | (N) 12.7 | (N) 1 : 40 | ND |
| 40 | RA | (P) 1.1 | (P) 24.6 | (N) 1 : 40 | ND |
| 41 | Thrombocytopenia | (P) 1.2 | (P) 51.2 | (N) 1 : 40 | ND |
| 42 | CTD | (P) 1.1 | (N) 6.8 | (P) 1 : 80 | ND |
*EliA: >1.0 ratio, positive; 0.7–1.0 ratio, equivocal; <0.7 ratio, negative. †QUANTA Flash: ≥20.0 CU, positive; <20.0 CU, negative. ‡IIFA: ≥1:80, positive; <1:80, negative.
Abbreviations: CTD, connective tissue disease; CU, chemiluminescent units; ENA, extractable nuclear antigen; FFA, Frontal fibrosing alopecia; IIFA, indirect immunofluorescence assay; ILD, interstitial lung disease; N, negative; ND, not detected; OA, osteoarthritis; P, positive; RA, rheumatoid arthritis; SLE, systemic lupus erythematosus; SjS, Sjögren’s syndrome; SSc, systemic sclerosis; R/O, rule out; SjS, primary Sjögren’s syndrome; SLE, systemic lupus erythematosus; SSc, systemic sclerosis.
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